Research On Fault Location Of AT Traction Network Based On Combined Traveling Wave Ranging Method

With the rapid and reliable development of high-tech of high-speed electrified railway in China,in the next few years,high-speed railway will gradually build a "eight horizontal and eight vertical" high-speed railway network.The traction power supply system,as the power facility of high-speed railway operation line,is very important to ensure the stable operation of electric locomotives by supplying electric energy safely and reliably.At present,in practical engineering applications,the railway departments still use the impedance method with simple calculation and low investment to complete the traction network line fault location,but its positioning effect is not ideal.Therefore,this paper attempts to adopt a combined traveling wave fault location method to achieve high-speed railway traction network line fault accurate location.The main work is as follows:Firstly,this paper analyzes the structure of the traction network and the four common power supply methods.It analyzes and calculates the multi-wire electrical parameters of the AT traction network and the equivalent value combination.On the basis of traditional phase-mode transformation theory,the solution process of phase-mode transformation matrix suitable for unbalanced line of traction network is deduced.The phase-mode decoupling of single line AT power supply line is carried out to calculate each mode wave speed.Secondly,according to the research status of traveling wave fault location and AT catenary fault characteristics,by comparing the advantages and disadvantages of A-type,C-type and D-type traveling wave fault location methods,a combined traveling wave fault location method is proposed to study AT catenary fault location.The synchronization accuracy of clock at both ends is improved by using UM220-III Beidou/GPS dual system module.Then the singularity detection theory and modulus maximum theory of wavelet transform are studied to detect and extract the arrival time of transient traveling wave head.Finally,based on ATP software simulation platform,three kinds of traction network simulation models under single-line AT,double-line AT and Full-Parallel AT power supply mode are built.The transmission line architecture of AT traction network is mainly studied,and the AT line simulation module which is closer to the real line structure is built using J.Marti line model.The combined traveling wave ranging method is used to simulate different possible situations and three line structure models under AT power supply mode.The results show that the ranging error of the algorithm is small and the reliability is high,and it is almost not affected by factors such as transition resistance,fault phase angle,fault location,fault type,electric locomotive and line structure.A simple simulation experiment system is built by using the existing equipment in the laboratory,which verifies that the combined traveling wave ranging method is effective and feasible,and provides some reference for the follow-up related research.